PURPOSE: To provide a compact construction and improve accuracy by disposing a photo-electric sensor having a light emitting element and a light receiving element on the same surface and a prism oppositely to each other to transmit a light signal to the light receiving element by reflecting the light signal only when the prism is on a level with the surface of water.
CONSTITUTION: In the case that the amount of the water stored in a hot water tank is small and hence the water level is positioned at the lower part of a water level sensing element 1, a photo-electric signal emitted from a light emitting element 5 of a photo-electric sensor 7 is reflected by an inclined surface of a prism 8 and received by a light receiving element 6. When the water level rises and the prism 8 is submerged, the photo-electric signal emitted from the element 5 is refracted at the lower side inclined surface and dispersed to the outside of the prism, so that the element 6 does not receive the signal. And when the signal is received, a water feed valve and a pump are actuated through a control unit to feed water to the hot water tank. And when the tank has been fully filled with water and the signal is no longer received, the valve and pumps are stopped. As a result, the construction of the device can be made simpler and smaller and it can be inserted into the tank from above and there is no contact point and hence sensing can be made with high accuracy.
| JP2002213001 | TOILET EQUIPMENT |
| JP3602386 | Hot water cleaning device |
KOYAMOTO MASANORI
SAKURAI YOSHIHIRO
